Materials handling facilities such as warehouses or retail stores often store or display items on shelves. For example, a materials handling facility may include structural features such as walls, gondola racks or fixtures to which one or more shelves may be mounted or from which such shelves may be suspended, and available items may be disposed upon such shelves. Available items may remain on shelves on a temporary basis, until one or more of the items thereon is desired (e.g., in response to an order or a request from one or more users of the materials handling facility).
Storing items on shelves or like elements provides a number of advantages to users of a materials handling facility. For example, an item having one or more flat surfaces may be stored individually or collectively (e.g., along with other like or identical items), by placing one or more of the flat surfaces of such items on a corresponding flat surface of a shelf or like element. Furthermore, items may be stored in random locations on a shelf, or in predetermined areas or spaces of the shelf that are set aside for items of a specific type, group or category.
A shelf may be utilized to provide support to items of varying sizes, shapes or masses, so long as such items or their containers include one or more flat surfaces that may be safely rested upon flat surfaces of the shelf, or may be expected to remain on the shelf, so long as the shelf may properly accommodate each of the items' collective masses, volumes or surface areas. In some instances, a shelf may be releasably mounted to pegboards, panels or other structural features provided within a materials handling facility (e.g., within one or more inventory areas therein) in a releasable manner that enables the shelf to be quickly and easily removed from a structural feature and installed in different locations on the structural feature, or on one or more other structural features throughout the materials handling facility. Some structural features may be configured to accommodate shelves in any number of predetermined locations in three-dimensional space within a materials handling facility, with such locations being defined based on the sizes or dimensions of the respective items to be placed thereon. Furthermore, items that are placed on shelves in plain sight or fully or partially in view of users may be visually identified based on one or more markings placed thereon, or based on one or more temporary or permanent signs associated with such locations.
Today, the use of shelves or other like elements to temporarily store items in a materials handling facility has a number of drawbacks, however. For example, because any number of items may be provided on a common shelf, e.g., in a row or series, a user of a materials handling facility may not become aware that a level of inventory of a given item is depleted until the final item in the row or series is removed from the shelf. Additionally, determining a level of inventory or performing an accounting of the number or type of available items suspended from support bar may usually only be conducted by a visual inspection, e.g., by manually evaluating and counting each of the items stored on the shelf. While items are sometimes stored on a shelf in a homogenous manner, e.g., such that each of the items stored on the shelf is identical or fungible, the actual contents of a shelf may not be confirmed without performing a visual inspection, which may sometimes require lifting and relocating items on the shelf in order to view and evaluate other items stored thereon. While placing items on a shelf or removing items from the shelf are simple, identifying the items on the shelf or determining locations of such items on the shelf are far more complex.